EP1035098A1 - Process for the preparation of sorbic acid - Google Patents
Process for the preparation of sorbic acid Download PDFInfo
- Publication number
- EP1035098A1 EP1035098A1 EP99943426A EP99943426A EP1035098A1 EP 1035098 A1 EP1035098 A1 EP 1035098A1 EP 99943426 A EP99943426 A EP 99943426A EP 99943426 A EP99943426 A EP 99943426A EP 1035098 A1 EP1035098 A1 EP 1035098A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sorbic acid
- polyester
- acid
- solid
- liquid separation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/09—Preparation of carboxylic acids or their salts, halides or anhydrides from carboxylic acid esters or lactones
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/47—Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
Definitions
- the present invention relates to a process for producing sorbic acid which is useful as, for example, food additives.
- the invention relates to a process for producing sorbic acid by decomposition of a polyester obtained from ketene and crotonaldehyde.
- processes for the commercial production of sorbic acid processes are known which include the step of hydrolyzing a polyester in the presence of an acid, which polyester is obtained by a reaction of ketene with crotonaldehyde.
- Japanese Examined Patent Application Publication No. 44-26646 discloses a process for producing sorbic acid. The process includes the steps of reacting ketene with crotonaldehyde in the presence of a catalyst to yield a reaction mixture, heating the reaction mixture under reduced pressure to remove unreacted crotonaldehyde and by-products of the reaction by distillation to yield a polyester containing the catalyst, decomposing the polyester with hydrochloric acid to yield a reaction mixture, and cooling the reaction mixture to yield sorbic acid.
- a purified sorbic acid is generally obtained by preparing a reaction mixture slurry by the hydrolysis of the polyester in the presence of an acid, subjecting the reaction mixture slurry to filtration or another solid-liquid separation operation to yield a crude sorbic acid as a solid, and subjecting the crude sorbic acid to a purification process such as treatment with active carbon or crystallization.
- the reaction mixture slurry contains tar substances by-produced in the reaction. In the solid-liquid separation, some of the tar substances migrate to liquid portions, but others adhere to a surface of sorbic acid and migrate to solid portions.
- loads on the subsequent purification process such as treatment with active carbon must be increased or a combination of several complicated purification processes must be employed.
- the Japanese Examined Patent Application Publication No. 44-26646 discloses a process for producing sorbic acid.
- the process includes the steps of preparing a polyester from ketene and crotonaldehyde, and decomposing the polyester with hydrochloric acid having a concentration of 35% by weight or more at temperatures ranging from room temperature to around the boiling point of the hydrochloric acid used.
- a crystalline sorbic acid is obtained by cooling a reaction mixture, separating a crude sorbic acid by filtration, washing the crude sorbic acid with water, putting the washed crude sorbic acid into water, heating and dissolving the mixture to yield a solution, adding activated carbon to the solution, boiling the mixture, and filtering the mixture while heating, and gradually cooling the resulting filtrate to yield a crystalline sorbic acid.
- Japanese Unexamined Patent Application Publication No. 9-227447 discloses a process for producing sorbic acid. The process includes the step of performing isomerization at a specific temperature after the completion of heat generation in the hydrolysis of the polyester.
- a crude sorbic acid is obtained by cooling a reaction mixture to 25°C and filtrating the cooled reaction mixture under suction.
- Japanese Unexamined Patent Application Publication No. 10-95745 discloses a process for producing sorbic acid, including the step of hydrolyzing the polyester with a mineral acid in the presence of a saturated fatty acid.
- An example shown in this publication describes that a crude sorbic acid was obtained by cooling a reaction mixture to 20°C and filtrating the cooled reaction mixture under suction.
- an object of the invention is to provide a process for producing sorbic acid, which is capable of easily and efficiently removing tar substances by-produced in a reaction and is capable of mitigating loads on a purification process.
- Another object of the invention is to provide a process for efficiently producing a highly purified sorbic acid having a satisfactory hue.
- the present inventors made intensive investigations to achieve the above objects, and found that tar substances can be efficiently removed by subjecting a decomposition reaction mixture of the polyester to solid-liquid separation at temperatures in a specific range.
- the invention provides a process for producing sorbic acid by hydrolysis of a polyester in the presence of an acid, which polyester is obtained from ketene and crotonaldehyde.
- the process includes the step of subjecting a reaction mixture formed by decomposition of the polyester to solid-liquid separation at temperatures ranging from 30°C to 60°C to yield sorbic acid as a solid.
- a polyester obtained from ketene and crotonaldehyde is hydrolized in the presence of an acid to yield sorbic acid.
- the polyester is generally shown by the following formula (1):
- R is an acetoxy group or a hydroxyl group
- n denotes an integer of 2 or more (e.g., about 3 to 40).
- the polyester can be obtained by conventional or known processes.
- the polyester is obtained by reacting ketene with crotonaldehyde in the presence of a catalyst and in the absence of or in the presence of an inert solvent.
- catalysts include, but are not limited to, simple substances or compounds of manganese, cobalt, nickel, zinc, cadmium, and other transition metals; and pyridine, picoline, and other nitrogen-containing basic compounds.
- Examples of the compounds of the transition metals are oxides; salts of acetic acid, salts of isobutyric acid, salts of isovaleric acid, and salts of other organic acids; salts of sulfuric acid, salts of nitric acid, and salts of other inorganic acids; chlorides and other halides; acetylacetone complex salts, and other complex salts and complexes.
- Each of these catalysts can be used alone or in combination.
- the amount of the catalyst differs according to the type of the catalyst, but is generally about 0.1 to 10% by weight relative to the weight of ketene.
- the reaction of ketene with crotonaldehyde is performed at a temperature of, for example, about 20°C to 100°C, and preferably about 25°C to 80°C.
- a reaction mixture containing the polyester obtained through the reaction of ketene with crotonaldehyde is usually distilled to remove unreacted crotonaldehyde and low boiling impurities, and is then subjected to a hydrolysis reaction with an acid.
- Acids for use in hydrolysis of the polyester include mineral acids such as hydrochloric acid and sulfuric acid.
- the hydrolysis of the polyester is frequently performed in hydrochloric acid.
- the concentration of hydrochloric acid is, for example, about 15 to 40% by weight and more preferably about 23 to 36% by weight.
- An extremely low concentration of hydrochloric acid may invite a decreased reaction rate, and in contrast, an extremely high concentration of hydrochloric acid may invite disadvantages in handling property or ease of operation.
- the amount of hydrochloric acid in terms of hydrogen chloride is, for example, about 10 to 160 parts by weight, and preferably about 15 to 100 parts by weight relative to 100 parts by weight of the polyester.
- the hydrolysis reaction is performed at temperatures of, for example, about 10°C to 110°C, and preferably about 50°C to 100°C.
- An extremely low reaction temperature may decrease a reaction efficiency, and in contrast, an extremely high reaction temperature may increase by-production of tar substances and other impurities.
- a reaction mixture obtained through hydrolysis of the polyester with an acid is usually a slurry containing sorbic acid dispersed in water.
- the reaction mixture contains, in addition to the sorbic acid and the acid used, tar substances and other impurities by-produced in the reaction.
- the reaction mixture is diluted or concentrated according to necessity, and is then subjected to solid-liquid separation to yield sorbic acid as a solid.
- Such solid-liquid separation means include, for example, filtration and centrifugal separation. In the invention, solid-liquid separation by filtration is preferred for ease of operation.
- the invention has a main feature in that the solid-liquid separation operation is performed while controlling the temperature of the decomposition reaction mixture of the polyester to a range from 30°C to 60°C, and preferably from 40°C to 50°C. If the temperature of the reaction mixture during solid-liquid separation is less than 30°C, the tar substances are highly viscous, and large portions of the tar substances in the reaction mixture adhere to a surface of the sorbic acid and migrate to solid portions. A crude sorbic acid thus obtained has a markedly deteriorated hue. If the temperature exceeds 60°C, the solubility of sorbic acid to hydrochloric acid increases and the sorbic acid tends to migrate to a mother liquor to thereby increase loss.
- the invention performs solid-liquid separation under the specific temperature condition, and the formed tar substances are less viscous and are less adherent to sorbic acid. Most of the tar substances can migrate to the mother liquor in solid-liquid separation operation, and a crude sorbic acid less colored can be obtained. The sorbic acid does not have a significantly high solubility to the mother liquor, and a loss on separation of the sorbic acid is low. In addition, corrosion of apparatus and instruments by the acid for use in decomposition of the polyester can be minimized.
- the separated solid matter may be rinsed.
- the rinsing treatment can reliably remove trace acid and impurities attached to sorbic acid.
- the solid matter is preferably rinsed with an aqueous solution containing sorbic acid which is formed in a sorbic acid purification process after the solid-liquid separation process.
- an aqueous solution containing sorbic acid in a proportion of 0.1% by weight to saturation is advantageously used as the rinsing liquid.
- the use of an aqueous solution containing sorbic acid obtained in a subsequent process as a rinsing liquid can reduce loss of sorbic acid induced by dissolution, as compared with rinsing of the solid matter with water.
- the aqueous solution containing sorbic acid includes, for example, a filtrate of washings obtained by treating the crude sorbic acid obtained in the solid-liquid separation operation with active carbon, crystallizing and filtrating the treated crude sorbic acid to yield a crystalline sorbic acid, and washing the crystalline sorbic acid with water.
- a highly purified sorbic acid having a satisfactory hue can be obtained by subjecting the crude sorbic acid obtained by the solid-liquid separation operation to a conventional separation and purification means.
- separation and purification means include, for example, treatment with active carbon, crystallization, filtration, centrifugal separation, distillation, and recrystallization.
- the crude sorbic acid obtained by the invented process is significantly less colored and contains minimized tar substances attached thereto, and can greatly mitigate loads on the purification process and can simplify the purification process to thereby efficiently yield a high quality sorbic acid.
- the product sorbic acid and its salts can be used as preservatives for foods such as fish pastes, butters, cheeses, bean pastes, and jams.
- the invention subjects a decomposition reaction mixture of the polyester to solid-liquid separation under the specific temperature condition and can easily and efficiently remove tar substances by-produced in the reaction while avoiding loss of the sorbic acid.
- the crude sorbic acid thus obtained by solid-liquid separation contains markedly reduced amounts of tar substances and is significantly less colored, and can greatly mitigate loads on the purification process without requiring a significantly complicated purification process.
- the invention can therefore efficiently produce a highly purified sorbic acid having a satisfactory hue.
- crotonaldehyde To 600 parts of crotonaldehyde, 2 parts of zinc isobutyrate was added as a catalyst, and 170 parts of a ketene gas was introduced at a temperature of 30°C to 40°C to perform a reaction. After the completion of reaction, excess crotonaldehyde was removed by distillation under reduced pressure to yield a highly viscous polyester. The yield of the polyester was 77% on the basis of ketene.
- the rinsed crude sorbic acid had a moisture content of 20% by weight, and a dried crude sorbic acid had a tar content of 3% by weight and a hydrochloric acid content of 0.4% by weight.
- the crude sorbic acid had a light brown color.
- a sodium hydroxide aqueous solution was added to 125 parts of the obtained crude sorbic acid to yield a sodium sorbate aqueous solution.
- 6 parts of active carbon was added and the resulting mixture was stirred for 30 minutes.
- the resulting mixture was then filtrated to remove the active carbon, and a neutralization amount of a concentrated hydrochloric acid was added to the filtrate, and the mixture was cooled to precipitate sorbic acid.
- the precipitated sorbic acid was separated by filtration, was washed with water and was dried in vacuo to yield 106 parts of a purified sorbic acid.
- the synthesis and decomposition of a polyester, and the filtration and rinsing of a decomposition reaction mixture of the polyester were performed in the same manner as in Example 1, except that a filtrate of washings was used, instead of pure water, as the rinsing liquid in the rinsing operation of the crude sorbic acid.
- the filtrate of washings was obtained by treating the crude sorbic acid with active carbon, crystallizing the treated crude sorbic acid to yield sorbic acid, washing the sorbic acid with water and filtrating washings, as in Example 1.
- the crude sorbic acid after rinsing had a moisture content of 20% by weight, and a dried crude sorbic acid had a tar content of 3% by weight and a hydrochloric acid content of 0.4% by weight.
- the prepared crude sorbic acid had a light brown color.
- the crude sorbic acid had a moisture content of 20% by weight, and a dried crude sorbic acid had a tar content of 6.5% by weight and a hydrochloric acid content of 1.2% by weight.
- the crude sorbic acid had a moisture content of 20% by weight, and a dried crude sorbic acid had a tar content of 6% by weight and a hydrochloric acid content of 0.4% by weight.
- the prepared crude sorbic acid had a dark brown color.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invented process produces sorbic acid by hydrolysis
of a polyester in the presence of an acid, which polyester is
obtained from ketene and crotonaldehyde. The process includes
the step of subjecting a decomposition reaction mixture of the
polyester to solid-liquid separation at temperatures ranging
from 30°C to 60°C to yield sorbic acid as a solid. The process
may further include the step of rinsing the sorbic acid obtained
by solid-liquid separation with an aqueous solution containing
sorbic acid, which aqueous solution is formed in a purification
process of sorbic acid subsequent to the solid-liquid
separation.
The invented process can easily and efficiently remove tar
substances by-produced in the reaction and can mitigate loads
on a purification process.
Description
The present invention relates to a process for producing
sorbic acid which is useful as, for example, food additives.
Particularly, the invention relates to a process for producing
sorbic acid by decomposition of a polyester obtained from ketene
and crotonaldehyde.
As processes for the commercial production of sorbic acid,
processes are known which include the step of hydrolyzing a
polyester in the presence of an acid, which polyester is
obtained by a reaction of ketene with crotonaldehyde. For
example, Japanese Examined Patent Application Publication No.
44-26646 discloses a process for producing sorbic acid. The
process includes the steps of reacting ketene with
crotonaldehyde in the presence of a catalyst to yield a reaction
mixture, heating the reaction mixture under reduced pressure
to remove unreacted crotonaldehyde and by-products of the
reaction by distillation to yield a polyester containing the
catalyst, decomposing the polyester with hydrochloric acid to
yield a reaction mixture, and cooling the reaction mixture to
yield sorbic acid.
In such processes for producing sorbic acid by hydrolyzing
the polyester with an acid, a purified sorbic acid is generally
obtained by preparing a reaction mixture slurry by the
hydrolysis of the polyester in the presence of an acid,
subjecting the reaction mixture slurry to filtration or another
solid-liquid separation operation to yield a crude sorbic acid
as a solid, and subjecting the crude sorbic acid to a
purification process such as treatment with active carbon or
crystallization. The reaction mixture slurry contains tar
substances by-produced in the reaction. In the solid-liquid
separation, some of the tar substances migrate to liquid
portions, but others adhere to a surface of sorbic acid and
migrate to solid portions. To obtain a highly purified sorbic
acid having a satisfactory hue, loads on the subsequent
purification process such as treatment with active carbon must
be increased or a combination of several complicated
purification processes must be employed.
The Japanese Examined Patent Application Publication No.
44-26646 discloses a process for producing sorbic acid. The
process includes the steps of preparing a polyester from ketene
and crotonaldehyde, and decomposing the polyester with
hydrochloric acid having a concentration of 35% by weight or
more at temperatures ranging from room temperature to around
the boiling point of the hydrochloric acid used. In an example
described in this publication, a crystalline sorbic acid is
obtained by cooling a reaction mixture, separating a crude
sorbic acid by filtration, washing the crude sorbic acid with
water, putting the washed crude sorbic acid into water, heating
and dissolving the mixture to yield a solution, adding activated
carbon to the solution, boiling the mixture, and filtering the
mixture while heating, and gradually cooling the resulting
filtrate to yield a crystalline sorbic acid. Japanese
Unexamined Patent Application Publication No. 9-227447
discloses a process for producing sorbic acid. The process
includes the step of performing isomerization at a specific
temperature after the completion of heat generation in the
hydrolysis of the polyester. In an example described in this
publication, a crude sorbic acid is obtained by cooling a
reaction mixture to 25°C and filtrating the cooled reaction
mixture under suction. Japanese Unexamined Patent Application
Publication No. 10-95745 discloses a process for producing
sorbic acid, including the step of hydrolyzing the polyester
with a mineral acid in the presence of a saturated fatty acid.
An example shown in this publication describes that a crude
sorbic acid was obtained by cooling a reaction mixture to 20°C
and filtrating the cooled reaction mixture under suction.
However, when a hydrolysis reaction mixture of the
polyester is cooled to about 20°C to 25°C and is then filtrated
as in the above processes, such by-produced tar substances are
highly viscous, and large portions of the tar substances adhere
to sorbic acid and migrate to solid portions. This markedly
increases loads on subsequent sorbic acid purification
processes such as treatment with active carbon.
Such a decomposition reaction mixture of the polyester
contains an acid used in the reaction. The acid will corrode
apparatus and instruments in the purification process and
should be preferably removed completely as soon as possible.
Accordingly, an object of the invention is to provide a
process for producing sorbic acid, which is capable of easily
and efficiently removing tar substances by-produced in a
reaction and is capable of mitigating loads on a purification
process.
Another object of the invention is to provide a process
for efficiently producing a highly purified sorbic acid having
a satisfactory hue.
It is a further object of the invention to provide a process
for producing sorbic acid, which is capable of efficiently
removing not only tar substances but also the acid used in a
reaction.
The present inventors made intensive investigations to
achieve the above objects, and found that tar substances can
be efficiently removed by subjecting a decomposition reaction
mixture of the polyester to solid-liquid separation at
temperatures in a specific range.
Specifically, the invention provides a process for
producing sorbic acid by hydrolysis of a polyester in the
presence of an acid, which polyester is obtained from ketene
and crotonaldehyde. The process includes the step of
subjecting a reaction mixture formed by decomposition of the
polyester to solid-liquid separation at temperatures ranging
from 30°C to 60°C to yield sorbic acid as a solid.
According to the invention, a polyester obtained from
ketene and crotonaldehyde is hydrolized in the presence of an
acid to yield sorbic acid. The polyester is generally shown
by the following formula (1):
In the above formula, R is an acetoxy group or a hydroxyl
group, and n denotes an integer of 2 or more (e.g., about 3
to 40).
The polyester can be obtained by conventional or known
processes. For example, the polyester is obtained by reacting
ketene with crotonaldehyde in the presence of a catalyst and
in the absence of or in the presence of an inert solvent. Such
catalysts include, but are not limited to, simple substances
or compounds of manganese, cobalt, nickel, zinc, cadmium, and
other transition metals; and pyridine, picoline, and other
nitrogen-containing basic compounds. Examples of the
compounds of the transition metals are oxides; salts of acetic
acid, salts of isobutyric acid, salts of isovaleric acid, and
salts of other organic acids; salts of sulfuric acid, salts
of nitric acid, and salts of other inorganic acids; chlorides
and other halides; acetylacetone complex salts, and other
complex salts and complexes. Each of these catalysts can be
used alone or in combination. The amount of the catalyst
differs according to the type of the catalyst, but is generally
about 0.1 to 10% by weight relative to the weight of ketene.
The reaction of ketene with crotonaldehyde is performed
at a temperature of, for example, about 20°C to 100°C, and
preferably about 25°C to 80°C.
A reaction mixture containing the polyester obtained
through the reaction of ketene with crotonaldehyde is usually
distilled to remove unreacted crotonaldehyde and low boiling
impurities, and is then subjected to a hydrolysis reaction with
an acid.
Acids for use in hydrolysis of the polyester include
mineral acids such as hydrochloric acid and sulfuric acid. The
hydrolysis of the polyester is frequently performed in
hydrochloric acid. When the polyester is hydrolyzed with
hydrochloric acid, the concentration of hydrochloric acid is,
for example, about 15 to 40% by weight and more preferably about
23 to 36% by weight. An extremely low concentration of
hydrochloric acid may invite a decreased reaction rate, and
in contrast, an extremely high concentration of hydrochloric
acid may invite disadvantages in handling property or ease of
operation. The amount of hydrochloric acid in terms of
hydrogen chloride is, for example, about 10 to 160 parts by
weight, and preferably about 15 to 100 parts by weight relative
to 100 parts by weight of the polyester. The hydrolysis
reaction is performed at temperatures of, for example, about
10°C to 110°C, and preferably about 50°C to 100°C. An extremely
low reaction temperature may decrease a reaction efficiency,
and in contrast, an extremely high reaction temperature may
increase by-production of tar substances and other impurities.
A reaction mixture obtained through hydrolysis of the
polyester with an acid is usually a slurry containing sorbic
acid dispersed in water. The reaction mixture contains, in
addition to the sorbic acid and the acid used, tar substances
and other impurities by-produced in the reaction. The reaction
mixture is diluted or concentrated according to necessity, and
is then subjected to solid-liquid separation to yield sorbic
acid as a solid. Such solid-liquid separation means include,
for example, filtration and centrifugal separation. In the
invention, solid-liquid separation by filtration is preferred
for ease of operation.
The invention has a main feature in that the solid-liquid
separation operation is performed while controlling the
temperature of the decomposition reaction mixture of the
polyester to a range from 30°C to 60°C, and preferably from 40°C
to 50°C. If the temperature of the reaction mixture during
solid-liquid separation is less than 30°C, the tar substances
are highly viscous, and large portions of the tar substances
in the reaction mixture adhere to a surface of the sorbic acid
and migrate to solid portions. A crude sorbic acid thus
obtained has a markedly deteriorated hue. If the temperature
exceeds 60°C, the solubility of sorbic acid to hydrochloric acid
increases and the sorbic acid tends to migrate to a mother liquor
to thereby increase loss. In addition, apparatus and
instruments used in solid-liquid separation are liable to be
corroded. In contrast, the invention performs solid-liquid
separation under the specific temperature condition, and the
formed tar substances are less viscous and are less adherent
to sorbic acid. Most of the tar substances can migrate to the
mother liquor in solid-liquid separation operation, and a crude
sorbic acid less colored can be obtained. The sorbic acid does
not have a significantly high solubility to the mother liquor,
and a loss on separation of the sorbic acid is low. In addition,
corrosion of apparatus and instruments by the acid for use in
decomposition of the polyester can be minimized.
After the solid-liquid separation operation, the
separated solid matter may be rinsed. The rinsing treatment
can reliably remove trace acid and impurities attached to sorbic
acid. In this case, the solid matter is preferably rinsed with
an aqueous solution containing sorbic acid which is formed in
a sorbic acid purification process after the solid-liquid
separation process. Typically, an aqueous solution containing
sorbic acid in a proportion of 0.1% by weight to saturation
is advantageously used as the rinsing liquid. The use of an
aqueous solution containing sorbic acid obtained in a
subsequent process as a rinsing liquid can reduce loss of sorbic
acid induced by dissolution, as compared with rinsing of the
solid matter with water. In addition and advantageously, a
discharge liquid from the process can be effectively used. The
aqueous solution containing sorbic acid includes, for example,
a filtrate of washings obtained by treating the crude sorbic
acid obtained in the solid-liquid separation operation with
active carbon, crystallizing and filtrating the treated crude
sorbic acid to yield a crystalline sorbic acid, and washing
the crystalline sorbic acid with water.
A highly purified sorbic acid having a satisfactory hue
can be obtained by subjecting the crude sorbic acid obtained
by the solid-liquid separation operation to a conventional
separation and purification means. Such separation and
purification means include, for example, treatment with active
carbon, crystallization, filtration, centrifugal separation,
distillation, and recrystallization. The crude sorbic acid
obtained by the invented process is significantly less colored
and contains minimized tar substances attached thereto, and
can greatly mitigate loads on the purification process and can
simplify the purification process to thereby efficiently yield
a high quality sorbic acid.
The product sorbic acid and its salts can be used as
preservatives for foods such as fish pastes, butters, cheeses,
bean pastes, and jams.
The invention subjects a decomposition reaction mixture
of the polyester to solid-liquid separation under the specific
temperature condition and can easily and efficiently remove
tar substances by-produced in the reaction while avoiding loss
of the sorbic acid. The crude sorbic acid thus obtained by
solid-liquid separation contains markedly reduced amounts of
tar substances and is significantly less colored, and can
greatly mitigate loads on the purification process without
requiring a significantly complicated purification process.
The invention can therefore efficiently produce a highly
purified sorbic acid having a satisfactory hue.
When the sorbic acid obtained by solid-liquid separation
is rinsed with a sorbic acid-containing aqueous solution formed
in a sorbic acid purification process subsequent to the
solid-liquid separation operation, not only the tar substances
but also the acid used in the reaction can be efficiently
removed.
The present invention will now be illustrated in further
detail with reference to several inventive examples and a
comparative example below, which are not intended to limit the
scope of the invention. All "parts" are by weight unless
otherwise specified.
To 600 parts of crotonaldehyde, 2 parts of zinc isobutyrate
was added as a catalyst, and 170 parts of a ketene gas was
introduced at a temperature of 30°C to 40°C to perform a reaction.
After the completion of reaction, excess crotonaldehyde was
removed by distillation under reduced pressure to yield a highly
viscous polyester. The yield of the polyester was 77% on the
basis of ketene.
To 135 parts of the above-prepared polyester, 110 parts
of a concentrated hydrochloric acid having a concentration of
34% by weight was added, and the resulting mixture was heated
to 80°C to decompose the polyester to thereby yield a crude
sorbic acid slurry. The crude sorbic acid slurry was cooled
to 45°C and was then filtrated under reduced pressure. A crude
sorbic acid (residue) remained on a filter paper was analyzed
and was found to have a moisture content of 20% by weight, and
after drying, was found to have a tar content of 4% by weight
and a hydrochloric acid content of 1.2% by weight. The residue
was then rinsed under reduced pressure with pure water two times
by weight that of the residue. As a result, the rinsed crude
sorbic acid had a moisture content of 20% by weight, and a dried
crude sorbic acid had a tar content of 3% by weight and a
hydrochloric acid content of 0.4% by weight. The crude sorbic
acid had a light brown color.
A sodium hydroxide aqueous solution was added to 125 parts
of the obtained crude sorbic acid to yield a sodium sorbate
aqueous solution. To this aqueous solution, 6 parts of active
carbon was added and the resulting mixture was stirred for 30
minutes. The resulting mixture was then filtrated to remove
the active carbon, and a neutralization amount of a concentrated
hydrochloric acid was added to the filtrate, and the mixture
was cooled to precipitate sorbic acid. The precipitated sorbic
acid was separated by filtration, was washed with water and
was dried in vacuo to yield 106 parts of a purified sorbic acid.
The synthesis and decomposition of a polyester, and the
filtration and rinsing of a decomposition reaction mixture of
the polyester were performed in the same manner as in Example
1, except that a filtrate of washings was used, instead of pure
water, as the rinsing liquid in the rinsing operation of the
crude sorbic acid. The filtrate of washings was obtained by
treating the crude sorbic acid with active carbon,
crystallizing the treated crude sorbic acid to yield sorbic
acid, washing the sorbic acid with water and filtrating washings,
as in Example 1.
As a result, the crude sorbic acid after rinsing had a
moisture content of 20% by weight, and a dried crude sorbic
acid had a tar content of 3% by weight and a hydrochloric acid
content of 0.4% by weight. The prepared crude sorbic acid had
a light brown color.
The synthesis and decomposition of a polyester, and the
filtration and rinsing of a decomposition reaction mixture of
the polyester were performed in the same manner as in Example
1, except that the crude sorbic acid slurry obtained by
decomposition of the polyester was cooled to 25°C and was then
filtrated under reduced pressure.
As a result, before rinsing, the crude sorbic acid had a
moisture content of 20% by weight, and a dried crude sorbic
acid had a tar content of 6.5% by weight and a hydrochloric
acid content of 1.2% by weight. After rinsing, the crude sorbic
acid had a moisture content of 20% by weight, and a dried crude
sorbic acid had a tar content of 6% by weight and a hydrochloric
acid content of 0.4% by weight. The prepared crude sorbic acid
had a dark brown color.
Claims (2)
- A process for producing sorbic acid by hydrolysis of a polyester in the presence of an acid, said polyester being obtained from ketene and crotonaldehyde, said process comprising the step of subjecting a decomposition reaction mixture of said polyester to solid-liquid separation at temperatures ranging from 30°C to 60°C to yield sorbic acid as a solid.
- A process for producing sorbic acid according to claim 1, further comprising the step of rinsing the sorbic acid obtained by solid-liquid separation with an aqueous solution containing sorbic acid, said aqueous solution being formed in a purification process of sorbic acid subsequent to said solid-liquid separation.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10288795A JP2000095728A (en) | 1998-09-24 | 1998-09-24 | Method for producing sorbic acid |
| JP28879598 | 1998-09-24 | ||
| PCT/JP1999/005123 WO2000017145A1 (en) | 1998-09-24 | 1999-09-21 | Process for the preparation of sorbic acid |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP1035098A1 true EP1035098A1 (en) | 2000-09-13 |
| EP1035098A4 EP1035098A4 (en) | 2005-03-02 |
| EP1035098B1 EP1035098B1 (en) | 2006-03-08 |
Family
ID=17734838
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99943426A Expired - Lifetime EP1035098B1 (en) | 1998-09-24 | 1999-09-21 | Process for the preparation of sorbic acid |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US6437182B1 (en) |
| EP (1) | EP1035098B1 (en) |
| JP (1) | JP2000095728A (en) |
| CN (1) | CN1176895C (en) |
| DE (1) | DE69930274T2 (en) |
| DK (1) | DK1035098T3 (en) |
| WO (1) | WO2000017145A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103601615B (en) * | 2013-11-19 | 2016-02-17 | 南通醋酸化工股份有限公司 | A kind of preparation method of 2,4-Sorbic Acid |
| CN103570527B (en) * | 2013-11-19 | 2015-05-13 | 南通醋酸化工股份有限公司 | Preparation method for potassium sorbate |
| CN111437881B (en) * | 2020-05-06 | 2023-09-01 | 江苏润普食品科技股份有限公司 | Method for preparing sorbic acid by photo-efficient catalytic isomerization |
| CN114560770B (en) * | 2022-03-23 | 2023-02-17 | 广西金源生物化工实业有限公司 | Method for preparing ethyl sorbate by catalysis of supported p-toluenesulfonic acid |
| CN115920954B (en) * | 2022-12-20 | 2023-10-24 | 江苏润普食品科技股份有限公司 | Solid base catalyst for catalyzing depolymerization of sorbic acid polyester to prepare sorbic acid, preparation method and application thereof |
| US20250197337A1 (en) | 2023-12-14 | 2025-06-19 | Wisconsin Alumni Research Foundation | Conversion of triacetic acid lactone to potassium sorbate |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5533426B2 (en) * | 1973-12-14 | 1980-08-30 | ||
| JPS5522626A (en) * | 1978-08-03 | 1980-02-18 | Daicel Chem Ind Ltd | Preparation of sorbic acid or its derivative |
| CA1276176C (en) | 1984-02-16 | 1990-11-13 | Henry Clay Brown | Purification of crude sorbic acid |
| JPH09227447A (en) | 1996-02-16 | 1997-09-02 | Nippon Synthetic Chem Ind Co Ltd:The | Method for producing sorbic acid |
-
1998
- 1998-09-24 JP JP10288795A patent/JP2000095728A/en active Pending
-
1999
- 1999-09-21 DE DE69930274T patent/DE69930274T2/en not_active Expired - Fee Related
- 1999-09-21 US US09/555,094 patent/US6437182B1/en not_active Expired - Fee Related
- 1999-09-21 EP EP99943426A patent/EP1035098B1/en not_active Expired - Lifetime
- 1999-09-21 WO PCT/JP1999/005123 patent/WO2000017145A1/en not_active Ceased
- 1999-09-21 CN CNB998016349A patent/CN1176895C/en not_active Expired - Fee Related
- 1999-09-21 DK DK99943426T patent/DK1035098T3/en active
Also Published As
| Publication number | Publication date |
|---|---|
| DK1035098T3 (en) | 2006-05-29 |
| JP2000095728A (en) | 2000-04-04 |
| WO2000017145A1 (en) | 2000-03-30 |
| EP1035098A4 (en) | 2005-03-02 |
| EP1035098B1 (en) | 2006-03-08 |
| US6437182B1 (en) | 2002-08-20 |
| CN1176895C (en) | 2004-11-24 |
| DE69930274D1 (en) | 2006-05-04 |
| DE69930274T2 (en) | 2006-07-27 |
| CN1286675A (en) | 2001-03-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3341912B2 (en) | Production of terephthalic acid | |
| EP1035098B1 (en) | Process for the preparation of sorbic acid | |
| US4013728A (en) | Process for halogenating a bisphenol | |
| EP0666108B1 (en) | Process for recovering and re-using cobalt and tungsten from reaction liquors | |
| EP0421046B1 (en) | Process for producing highly pure 3,3',4,4' - biphenyltetra- carboxylic acid or dianhydride thereof | |
| JPH07118285A (en) | Method for producing sucrose fatty acid ester | |
| CN1209337C (en) | Method for preparing sorbic acid | |
| US6590122B1 (en) | Processes for producing polyesters and producing sorbic acid | |
| EP1035099B1 (en) | Process for the preparation of sorbic acid or salts thereof | |
| CN1279012C (en) | Process for production of ruthenium (III) acetate solution | |
| US6495717B1 (en) | Process for producing sorbic acid or salts thereof | |
| US6462233B1 (en) | Process for the preparation of sorbic acid | |
| JP4207273B2 (en) | Method for producing naphthalenedicarboxylic acid | |
| US2336364A (en) | Method of refining crude 1-naphthylacetic acids | |
| JP3020415B2 (en) | Method for producing aminobenzanthrones | |
| KR810001128B1 (en) | Process for producing terephthalic acid | |
| JPS632425B2 (en) | ||
| JPH07179396A (en) | Production of acyloxybenzenedicarboxylic acid | |
| JP2000327626A (en) | Method for producing sorbic acid or a salt thereof | |
| JPH0753549A (en) | Production of n-succinimidyl-2-quinolinecarboxylate | |
| JPS59106439A (en) | Preparation of carboxylic acid ester | |
| JPS6346060B2 (en) | ||
| JPH0466465B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
| 17P | Request for examination filed |
Effective date: 20000920 |
|
| RBV | Designated contracting states (corrected) |
Designated state(s): DE DK |
|
| A4 | Supplementary search report drawn up and despatched |
Effective date: 20050114 |
|
| GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
| GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
| GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
| AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE DK |
|
| REF | Corresponds to: |
Ref document number: 69930274 Country of ref document: DE Date of ref document: 20060504 Kind code of ref document: P |
|
| PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
| PLAX | Notice of opposition and request to file observation + time limit sent |
Free format text: ORIGINAL CODE: EPIDOSNOBS2 |
|
| 26 | Opposition filed |
Opponent name: NUTRINOVA NUTRITION SPECIALTIES & FOOD INGREDIENTS Effective date: 20061208 |
|
| PLBB | Reply of patent proprietor to notice(s) of opposition received |
Free format text: ORIGINAL CODE: EPIDOSNOBS3 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20070913 Year of fee payment: 9 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DK Payment date: 20070914 Year of fee payment: 9 |
|
| PLAB | Opposition data, opponent's data or that of the opponent's representative modified |
Free format text: ORIGINAL CODE: 0009299OPPO |
|
| REG | Reference to a national code |
Ref country code: DK Ref legal event code: EBP |
|
| PLAB | Opposition data, opponent's data or that of the opponent's representative modified |
Free format text: ORIGINAL CODE: 0009299OPPO |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20090401 |
|
| PLAB | Opposition data, opponent's data or that of the opponent's representative modified |
Free format text: ORIGINAL CODE: 0009299OPPO |
|
| R26 | Opposition filed (corrected) |
Opponent name: NUTRINOVA NUTRITION SPECIALTIES & FOOD INGREDIENTS Effective date: 20061208 |
|
| R26 | Opposition filed (corrected) |
Opponent name: NUTRINOVA NUTRITION SPECIALTIES & FOOD INGREDIENTS Effective date: 20061208 |
|
| PLAY | Examination report in opposition despatched + time limit |
Free format text: ORIGINAL CODE: EPIDOSNORE2 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20090331 |
|
| PLBD | Termination of opposition procedure: decision despatched |
Free format text: ORIGINAL CODE: EPIDOSNOPC1 |
|
| PLBM | Termination of opposition procedure: date of legal effect published |
Free format text: ORIGINAL CODE: 0009276 |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: OPPOSITION PROCEDURE CLOSED |
|
| 27C | Opposition proceedings terminated |
Effective date: 20110128 |